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利用专门研制的气体采集系统和气体色层谱仪在一台直喷式柴油机上研究了未燃碳氢排放及其成分的时间分辨变化。试验的瞬态运转包括起动和加载。在以高当量比起动时,总碳氢(THC)最初增加,至最大值后逐渐减小以达到稳态值。在起动时只要保持足够的起动性能,减小大油量的当量比和缩短大油量的持续时间对减小THC排放是有效的。较低的碳氢(主要是C_1-C_8)是THC主要成分,并大体决定了在瞬态运转时的THC特性,而碳氢(HC)成分的比例没有重大变化。未限制的有毒物质1,3丁二烯和苯仅测出少量。
Time-resolved changes in unburned hydrocarbon emissions and their components were studied on a direct-injection diesel engine using a specially developed gas collection system and gas chromatograph. The transient operation of the test includes starting and loading. At start-up at a high equivalence ratio, total hydrocarbon (THC) initially increased, reaching a maximum and then decreasing to reach steady-state values. It is effective to reduce the THC emission as long as sufficient starting performance is maintained at start-up, reducing the equivalence ratio of large quantities of oil and shortening the duration of large amounts of oil. Lower hydrocarbons (mainly C_1-C_8) are the main constituents of THC and generally determine THC characteristics during transient operation, with no significant changes in the proportions of the hydrocarbon (HC) components. Unrestricted toxic substances 1,3 butadiene and benzene only detect small amounts.